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प्रश्न
When the positive charge on an ion increases or the negative charge on them decreases it is called as _______.
विकल्प
reduction
corrosion
oxidation
decomposition
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उत्तर
When the positive charge on an ion increases or the negative charge on them decreases it is called as oxidation.
APPEARS IN
संबंधित प्रश्न
Corrosion can be prevented by using ……………. solution.
Define ‘redox reaction’. Give one example.
What is an oxidising agent?
Why does the colour of copper sulphate solution change when an iron nail is dipped in it?
Explain the following in term Oxidation of gain or loss of oxygen with two example.
When SO2 gas is passed through saturated solution of H2S, the following reaction occurs:
SO2 + 2H2S → 2H2O + 3S
In this reaction, which substance is oxidised and which one is reduced?
Give an example of an oxidation reaction.
Is oxidation an exothermic or an endothermic reaction?
Give one example of an oxidation-reduction reaction which is also a displacement reaction.
In order to prevent the spoilage of potato chips, they are packed in plastic bags in an atmosphere of:
(a) Cl2
(b) H2
(c) N2
(d) O2
The process of respiration is:
(a) an oxidation reaction which is endothermic
(b) a reduction reaction which is exothermic
(c) a combination reaction which is endothermic
(d) an oxidation reaction which is exothermic
You are given the following chemical equation:
Mg (s) + CuO (s) → MgO (s) + Cu (s)
This equation represents:
(a) decomposition reaction as well as displacement reaction
(b) combination reaction as well as double displacement reaction
(c) redox reaction as well as displacement reaction
(d) double displacement reaction as well as redox reaction
Hydrogen burns with a ______ flame and ______ sound is heard.
Fill in the blank
Oxidation is the removal of ......................and addition of ....................
Name the following:
The process in which oxygen is added or hydrogen is removed.
TRUE \ FALSE
Hydrogen is a good oxidizing agent.
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{CuO_{(s)} + H2_{(g)} -> Cu_{(s)} + H2O_{(l)}}\]
Identify from the reaction the reactants that undergo oxidation and reduction.
Fe + S → FeS
Identify from the reaction the reactants that undergo oxidation and reduction.
2Mg + O2 → 2MgO
In what respect does hydrogen differ from:
alkali metals
Compare hydrogen and halogens on the basis of:
reaction with oxygen
Why zinc and aluminium are considered to have a unique nature. Give balanced equations to support your answer.
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
H2S + Cl2→ 2HCl + S
State whether the following conversion is oxidation or reduction:
K → K+ + e-
Divide the following reactions into oxidation and reduction half-reaction:
Cl2 + 2Br- → Br2 + 2Cl-
For the reaction PbO + H2→ Pb + H2O, which of the following statements is wrong?
Name:
a substance that oxidizes concentrated HCl to chlorine.
Name:
a gas that is oxidizing as well as a reducing agent.
Name:
a solid that is an oxidizing agent.
Complete and balance the following equation:
CuO +__________→ Cu +___________
Complete and balance the following equation:
\[\ce{K + H2O -> }\]________+ ________
State a reason why, when hydrogen is passed over heated copper oxide, the resultant product formed, differs in colour from the original reactant.
State the condition and give balanced equation for the conversion of coke to water gas.
Explain the term oxidation in term of addition and removal of oxygen/hydrogen with a suitable example.
Explain the term redox reaction with an example involving the reaction of hydrogen sulphide with chlorine.
Select the correct answer from the symbol in the bracket.
The element, which like hydrogen is a strong reducing agent.
Balance the given chemical reaction as per the instructions below.
\[\ce{NaOH + H2SO4 -> Na2SO4 + H2O}\]
Oxidation means losing electrons then what is reduction?
Select the oxidising agent for the following reaction:
\[\ce{H2S + I2 -> 2HI + S}\]
Identify the oxidising agent (oxidant) in the following reactions
`2"Mg" + "O"_2 -> 2"MgO"`
Identify the oxidising agent (oxidant) in the following reactions
`3"Fe" + 4"H"_2"O" -> "Fe"_3"O"_4 + 4"H"_2`
Grapes hanging on the plant do not ferment but after being plucked from the plant can be fermented. Under what conditions do these grapes ferment? Is it a chemical or a physical change?
Which among the following are physical or chemical change?
Sublimation of solid ammonium chloride
A silver article generally turns black when kept in the open for a few days. The article when rubbed with toothpaste again starts shining.
- Why do silver articles turn black when kept in the open for a few days? Name the phenomenon involved.
- Name the black substance formed and give its chemical formula.
What happens when zinc granules are treated with dilute solution of H2SO4, HCl, HNO3, NaCl and NaOH Also write the chemical equations if reaction oçcurs.
Write a short note on oxidizing and reducing agents.
______ is a metal that has a high resistance to corrosion.
What are redox reactions? Give examples.
What is rancidity?
Define oxidation number.
Find the oxidation number of the element in the following compound.
Zn in ZnSO4
When hydrogen gas is passed over black copper oxide, a reddish-coloured layer of copper is formed.
Answer the questions that follow based on this reaction.
- Write the equation.
- What type of reaction is it?
- Complete the blanks:
In this reaction, an oxygen atom goes away from CuO (copper oxide), which means that ______ of copper oxide takes place, whereas a hydrogen molecule takes up an oxygen atom and water (H2O) is formed, meaning ______ of hydrogen takes place.
Metals are good ______.
The metallic oxide which can be reduced by using common reducing agents is ______.
